A vehicle seat sliding device allows a seat to move in a front-rear direction. The vehicle seat sliding device includes a lower rail coupled to a vehicle body, an upper rail coupled to the seat, and a lock member. The lower rail supports the upper rail so that the upper rail is movable in a longitudinal direction of the lower rail. The lock member restricts movement of the upper rail relative to the lower rail (for example, refer to patent document 1). A vehicle seat sliding device needs to stabilize the position of the lock member.